The present invention relates to a suspension control apparatus.
A large number of conventional suspension control apparatuses aim to reduce a change in the posture of a vehicle. For example, there is known a suspension control apparatus configured to calculate a lateral jerk by temporally differentiating a lateral acceleration calculated from a steering angle and a vehicle speed, and control damping force adjustable shock absorbers disposed at four wheels according to the calculated lateral jerk so that the characteristics thereof are set to hard, thereby increasing damping forces generated by these shock absorbers and reducing a roll motion generated during cornering (for example, refer to Japanese Patent Application Public Disclosure No. HEI 8-2231).
Generally, a passenger such as a driver is sensitive to a behavior of a vehicle, and prefers a smooth behavior. When traveling around a corner, he/she prefers a smoothly changing behavior resulting from harmonized lateral acceleration and longitudinal acceleration of the vehicle, like the behavior of a vehicle when a skilled driver operates the vehicle. On the basis of this knowledge, Japanese Patent Application Public Disclosure 2007-290650 discloses a vehicle operation control apparatus configured to control acceleration and deceleration of a vehicle with use of lateral jerk information.
Since conventional suspension apparatuses, like the one disclosed in Japanese Patent Application Public Disclosure No. HEI 8-2231, do not focus on a smooth behavior of a vehicle, they may fail to provide an excellent driving feeling to a passenger when they extremely reduce a change in the posture of a vehicle. As will be used herein, the term “driving feeling” is used to refer to an impression which a passenger receives from a behavior of a vehicle, and the term “excellent driving feeling” is used to refer to an impression that “the vehicle runs smoothly”, “the vehicle turns a corner skillfully”, or/and “cornering is continuous”.
On the other hand, conventional vehicle operation control apparatuses, like the one disclosed in Japanese Patent Application Public Disclosure No. 2007-290650, intervene in driver's acceleration/deceleration operation, and generates acceleration or deceleration out of synchronization with the driver's intended timing. Therefore, they may also fail to provide the excellent driving feeling. In the first place, such a vehicle operation control apparatus belongs to a completely different technical field from that of suspension control apparatus.